Binary Logarithm

Compute an integer binary logarithm.

Usage

var log2Uint32 = require( '@stdlib/fastmath/special/uint32-log2' );

log2Uint32( x )

Returns an approximate binary logarithm of an unsigned 32-bit integer x.

var v = log2Uint32( 4 >>> 0 );
// returns 2

v = log2Uint32( 8 >>> 0 );
// returns 3

v = log2Uint32( 9 >>> 0 );
// returns 3

Notes

  • This implementation provides a performance boost when an application requires only approximate computations for integer arguments.
  • For applications requiring high-precision, this implementation is never suitable.

Examples

var log2Uint32 = require( '@stdlib/fastmath/special/uint32-log2' );

var v;
var i;

for ( i = 1; i < 101; i++ ) {
    v = log2Uint32( i >>> 0 );
    console.log( 'log2(%d) ≈ %d', i, v );
}